大型结构件刀口及惠勒密封重复密封性能研究

针对要求高真空度内环境的大型结构件采用的刀口密封在现场装调抽真空过程中达不到泄漏率要求的问题,研究采用惠勒密封的可行性。采用试验方法确定刀口密封和惠勒密封合适的螺栓预紧力,并比较2种常用密封方式的重复密封性能;采用有限元方法分析其接触面的应力和应变。结果表明:相比刀口密封,惠勒密封结构能在更大的螺钉拧紧力矩范围内实现有效密封;刀口密封和惠勒密封均能很好地实现首次密封,但当二次密封出现结构缺陷时,刀口密封必须修复破损的刀口或更换金属垫圈才能实现再次有效密封,而惠勒密封仅需适当增加螺钉的拧紧力矩即可保证有效密封,因此惠勒密封具有更高的可靠性。

Study on Repetitive Sealing Performance of Knife-Edge and Wheeler Seals of Large Structure

Aimed the problem that the knife edge seal used in the large scale structures with high vacuum operating condition can not meet the requirement of leakage rate during field setting,the feasibility of using Wheeler seal was studied.The proper preload of screw of knife edge seal and Wheeler seal was determined by test method,and the repeated sealing performance of two common sealing methods was compared.The stress and strain of contact surface were analyzed by finite element method.The results indicate that compared with knife edge seal,Wheeler seal can achieve effective sealing in a larger screw preload range.The knife edge and Wheeler seal can both achieve effective sealing in the first time.However,when there is a structural defect occurred inthe secondary seal,the knife edge seal must repair cutting edge or replace cooper seal ring to ensure effective sealing,while the Wheeler seal only needs to increase the screw moment to ensure effective sealing,so Wheeler seal is more reliable